/*
 * ************************************************************
 * 文件：ShellUtil.java  模块：app  项目：WeChatGenius
 * 当前修改时间：2018年08月20日 12:52:17
 * 上次修改时间：2018年08月06日 11:44:57
 * 作者：大路
 * Copyright (c) 2018
 * ************************************************************
 */

package com.evan.wechat.util;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.List;

/**
 * ShellUtil
 * <ul>
 * <strong>Check root</strong>
 * <li>{@link ShellUtil#checkRootPermission()}</li>
 * </ul>
 * <ul>
 * <strong>Execte command</strong>
 * <li>{@link ShellUtil#execCommand(String, boolean)}</li>
 * <li>{@link ShellUtil#execCommand(String, boolean, boolean)}</li>
 * <li>{@link ShellUtil#execCommand(List, boolean)}</li>
 * <li>{@link ShellUtil#execCommand(List, boolean, boolean)}</li>
 * <li>{@link ShellUtil#execCommand(String[], boolean)}</li>
 * <li>{@link ShellUtil#execCommand(String[], boolean, boolean)}</li>
 * </ul>
 *
 * @author <a href="http://www.trinea.cn" target="_blank">Trinea</a> 2013-5-16
 */
public class ShellUtil {

  public static final String COMMAND_SU = "su";
  public static final String COMMAND_SH = "sh";
  public static final String COMMAND_EXIT = "exit\n";
  public static final String COMMAND_LINE_END = "\n";

  private ShellUtil() {
    throw new AssertionError();
  }

  /**
   * check whether has root permission
   */
  public static boolean checkRootPermission() {
    return execCommand("echo root", true, false).result == 0;
  }

  /**
   * execute shell command, default return result msg
   *
   * @param command command
   * @param isRoot whether need to run with root
   * @see ShellUtil#execCommand(String[], boolean, boolean)
   */
  public static CommandResult execCommand(String command, boolean isRoot) {
    return execCommand(new String[] { command }, isRoot, true);
  }

  /**
   * execute shell commands, default return result msg
   *
   * @param commands command list
   * @param isRoot whether need to run with root
   * @see ShellUtil#execCommand(String[], boolean, boolean)
   */
  public static CommandResult execCommand(List<String> commands, boolean isRoot) {
    return execCommand(commands == null ? null : commands.toArray(new String[] {}), isRoot, true);
  }

  /**
   * execute shell commands, default return result msg
   *
   * @param commands command array
   * @param isRoot whether need to run with root
   * @see ShellUtil#execCommand(String[], boolean, boolean)
   */
  public static CommandResult execCommand(String[] commands, boolean isRoot) {
    return execCommand(commands, isRoot, true);
  }

  /**
   * execute shell command
   *
   * @param command command
   * @param isRoot whether need to run with root
   * @param isNeedResultMsg whether need result msg
   * @see ShellUtil#execCommand(String[], boolean, boolean)
   */
  public static CommandResult execCommand(String command, boolean isRoot, boolean isNeedResultMsg) {
    return execCommand(new String[] { command }, isRoot, isNeedResultMsg);
  }

  /**
   * execute shell commands
   *
   * @param commands command list
   * @param isRoot whether need to run with root
   * @param isNeedResultMsg whether need result msg
   * @see ShellUtil#execCommand(String[], boolean, boolean)
   */
  public static CommandResult execCommand(List<String> commands, boolean isRoot,
                                          boolean isNeedResultMsg) {
    return execCommand(commands == null ? null : commands.toArray(new String[] {}), isRoot,
        isNeedResultMsg);
  }

  /**
   * execute shell commands
   *
   * @param commands command array
   * @param isRoot whether need to run with root
   * @param isNeedResultMsg whether need result msg
   * @return <ul>
   * <li>if isNeedResultMsg is false, {@link CommandResult#successMsg} is null and
   * {@link CommandResult#errorMsg} is null.</li>
   * <li>if {@link CommandResult#result} is -1, there maybe some excepiton.</li>
   * </ul>
   */
  public static CommandResult execCommand(String[] commands, boolean isRoot,
                                          boolean isNeedResultMsg) {
    int result = -1;
    if (commands == null || commands.length == 0) {
      return new CommandResult(result, null, null);
    }

    Process process = null;
    BufferedReader successResult = null;
    BufferedReader errorResult = null;
    StringBuilder successMsg = null;
    StringBuilder errorMsg = null;

    DataOutputStream os = null;
    try {
      process = Runtime.getRuntime().exec(isRoot ? COMMAND_SU : COMMAND_SH);
      os = new DataOutputStream(process.getOutputStream());
      for (String command : commands) {
        if (command == null) {
          continue;
        }

        // don't use os.writeBytes(commmand), avoid chinese charset error
        os.write(command.getBytes());
        os.writeBytes(COMMAND_LINE_END);
        os.flush();
      }
      os.writeBytes(COMMAND_EXIT);
      os.flush();

      result = process.waitFor();
      // get command result
      if (isNeedResultMsg) {
        successMsg = new StringBuilder();
        errorMsg = new StringBuilder();
        successResult = new BufferedReader(new InputStreamReader(process.getInputStream()));
        errorResult = new BufferedReader(new InputStreamReader(process.getErrorStream()));
        String s;
        while ((s = successResult.readLine()) != null) {
          successMsg.append(s);
        }
        while ((s = errorResult.readLine()) != null) {
          errorMsg.append(s);
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      try {
        if (os != null) {
          os.close();
        }

        if (successResult != null) {
          successResult.close();
        }

        if (errorResult != null) {
          errorResult.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }

      if (process != null) {
        process.destroy();
      }
    }

    return new CommandResult(result, successMsg == null ? null : successMsg.toString(),
        errorMsg == null ? null : errorMsg.toString());
  }

  /**
   * result of command
   * <ul>
   * <li>{@link CommandResult#result} means result of command, 0 means normal, else means error,
   * same to excute in
   * linux shell</li>
   * <li>{@link CommandResult#successMsg} means success message of command result</li>
   * <li>{@link CommandResult#errorMsg} means error message of command result</li>
   * </ul>
   *
   * @author <a href="http://www.trinea.cn" target="_blank">Trinea</a> 2013-5-16
   */
  public static class CommandResult {

    /** result of command **/
    public int result;
    /** success message of command result **/
    public String successMsg;
    /** error message of command result **/
    public String errorMsg;

    public CommandResult(int result) {
      this.result = result;
    }

    public CommandResult(int result, String successMsg, String errorMsg) {
      this.result = result;
      this.successMsg = successMsg;
      this.errorMsg = errorMsg;
    }

    @Override
    public String toString() {
      return "CommandResult{"
          + "result="
          + result
          + ", successMsg='"
          + successMsg
          + '\''
          + ", errorMsg='"
          + errorMsg
          + '\''
          + '}';
    }
  }
}